Unknown

ABSTRACT

A flexible endoscope shank with a shank body which, viewed in the longitudinal direction of the endoscope shank, is composed of at least two shank portions with different degrees of flexibility, wherein at least one shank portion is composed of at least one spring element, and wherein all the spring elements of the shank portions, which, viewed in the longitudinal direction of the shank body, are arranged proximally from the outer distal shank portion, are designed as reversibly deformable spring rods extending in the longitudinal direction of the shank body. In order to create a flexible endoscope shank that can be produced easily and cost-effectively, each of the shank portions having at least one spring rod has at least one further spring rod, which is integrally bonded to the other spring rods of the respective shank portion.

FIELD OF THE INVENTION

The invention relates to a flexible endoscope shank with a shank bodywhich, viewed in the longitudinal direction of the endoscope shank, iscomposed of at least two shank portions with different degrees offlexibility, wherein at least one shank portion is composed of at leastone spring element, and wherein all the spring elements of the shankportions, which, viewed in the longitudinal direction of the shank body,are arranged proximally from the outer distal shank portion, aredesigned as reversibly deformable spring rods extending in thelongitudinal direction of the shank body. The invention further relatesto an endoscope having a flexible endoscope shank of the kind mentionedabove.

BACKGROUND OF THE INVENTION

Flexible endoscopes, that is to say endoscopes with a flexible endoscopeshank, are used in medicine and for technical purposes, in order toexamine branched or looped regions in the body or to examine machineparts.

Flexible endoscopes differ from rigid endoscopes in that the endoscopeshank of a flexible endoscope can adopt a bent, curved or even loopedshape. By virtue of this flexibility of the endoscope shank, flexibleendoscopes are particularly suitable in medicine for operating on andexamining regions in the body that have branched or looped structures,for example the gastrointestinal tract or the air passages.

Various approaches to the design of flexible endoscope shanks are knownin practice.

DE 199 08 152 A1 discloses an endoscope, in the endoscope shank of whichflexible rods are arranged extending in the longitudinal direction.These flexible rods allow the operator to manually bend the endoscopeshank to a desired curved profile before the operation, such that theendoscope shank can be advanced to the examination site through anopening in the body. On account of the stiffness of the rods, theendoscope shank permanently maintains this predefined curved profileduring use.

Although this stiffness of the flexion rods, which permit the shaping ofthe endoscope shank, ensures an inner stiffness of the endoscope shank,as is important for the use, it also limits the possible applications ofa flexible endoscope of this design, since the predefined curved profileof the endoscope shank cannot be changed during the operation, forexample in order to examine lateral branches or the like.

A flexible endoscope of the type in question is known from EP 1 658 805B1. In this known flexible endoscope, the endoscope shank is composed ofseveral shank portions, which are each formed by a helical spring. Thedegree of flexibility of the individual shank portions can beindividually adjusted by the choice of different helical springs. Thereversibly deformable helical springs of this known endoscope permit aflexible endoscope shank that can be adjusted in each desired directioneven during the examination.

Designing the spring elements of the individual shank portions ashelical springs has the disadvantage that cleaning the narrowhelical-spring threads is quite complex. In addition, the production ofthe different helical springs is very elaborate and cost-intensive.

SUMMARY OF THE INVENTION

Proceeding from this, the object of the invention is to create aflexible endoscope shank that is of the kind mentioned at the outset andthat can be produced simply and cost-effectively.

According to the invention, this object is achieved by virtue of thefact that, viewed in the longitudinal direction of the shank body fromthe distal end to the proximal end, each of the shank portions having atleast one spring rod has at least one further spring rod, which isintegrally bonded to the other spring rods of the respective shankportion.

By designing the spring elements as spring rods made from flat or roundspring wire, the shank body can be produced simply and cost-effectively.

In order to increase the dimensional stability and torsional stiffnessof the individual shank portions toward the proximal end of the shankbody, each shank portion, viewed in the longitudinal direction of theshank body from the distal end to the proximal end, has at least oneadditional spring rod, which is integrally bonded, in particular bylaser welding, to the other spring rods, wherein the at least oneadditional spring rod of the respective shank portion is arrangedlaterally on the spring rod coming from the previous shank portion.

In a practical embodiment of the invention, it is proposed that the atleast one further spring rod, extending in the longitudinal direction ofthe shank body, is arranged laterally on the other spring rods of therespective shank portion.

Furthermore, the invention proposes that each shank portion of the shankportions arranged proximally from the outer distal shank portion, whenviewed in the longitudinal direction of the shank body, has at least twospring rods, each of which has a longitudinal extent reaching as far asthe proximal end of the shank body. The use of at least two spring rodsfor the non-distal shank portion permits the design of a shank body thathas a sufficient bending strength and shear stability.

Furthermore, the invention proposes that the spring rods of each shankportion are wound helically about each other and/or are wound helicallyabout the spring rods of the shank portions which, viewed in thelongitudinal direction of the shank body, are located distally. Thishelical winding of the spring rods about each other increases thedimensional stability, bending strength and torsional stability of theshank portions. In order to fix the spring rods to each other in theposition in which they are wound about each other, and in order toprevent the winding from coming undone, it is furthermore proposed thatthe spring rods wound helically about each other are integrally bondedto each other at some areas, preferably punctual, preferably by laserwelding, wherein the properties of the individual shank portions can bevaried by means of the spring rods, wound about each other, being weldedto each other only at a few locations or at many locations.

Winding the spring rods about each other also has the advantage that,upon bending of the endoscope shank, there is no preferred bendingdirection, and instead the endoscope shank can be bent withapproximately the same force in all directions.

According to the invention, the properties of the individual shankportions, for example in respect of the degree of flexibility and thebending strength, can be varied, inter alia, by virtue of the fact thatthe spring rods of the individual shank portions are wound with the sameor a different number of windings about the spring rods of the shankportions which, viewed in the longitudinal direction of the shank body,are located distally or proximally. More windings per unit of lengthresult in a stiffening of the shank portion, whereas fewer windings perunit of length make the respective shank portion more flexible.

According to a preferred embodiment of the invention, it is proposedthat the degree of flexibility of the spring elements of the individualshank portions decreases from the distal end to the proximal end, thatis to say the outer distal shank portion is the most flexible, and theshank portions become increasingly stiffer toward the proximal end ofthe shank body.

According to a further embodiment according to the invention, it isproposed that the outermost distal shank portion is composed ofindividual segments connected to each other in an articulated manner.

For pivoting the outer distal shank portion, the invention proposes thatthe outermost distal shank portion is pivotable via a pull mechanism,preferably at least one Bowden cable, engaging on the distal shankportion.

For the design of the finished endoscope shank, the invention proposesthat all the shank portions can be enclosed by an elastic outer sheath,preferably a hose.

The invention furthermore proposes that work channels, extending in thelongitudinal direction of the shank body, are arranged in the outersheath, for example for receiving optical components, additional medicalinstruments, electrical lines and the pull mechanism.

The invention further relates to a flexible endoscope having a flexibleendoscope shank constructed in the manner described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become clear fromthe appended drawings, in which a number of illustrative embodiments ofa flexible endoscope shank according to the invention are shown only byway of example, without limiting the invention to these illustrativeembodiments. In the drawings:

FIG. 1 shows an overall view of an endoscope with a flexible shank;

FIG. 2 shows an enlarged view of the detail II from FIG. 1 in differentworking positions;

FIG. 3 shows an enlarged and schematic detailed view of part of thedistal and middle shank portion of a flexible endoscope shank accordingto the invention;

FIG. 4 shows an enlarged and schematic detailed view of part of themiddle and proximal shank portion of a flexible endoscope shankaccording to the invention, and

FIG. 5 shows a side view of part of a flexible endoscope shank accordingto the invention with an outer sheath partially pushed onto it.

DETAILED DESCRIPTION OF THE INVENTION

The illustration in FIG. 1 shows a flexible endoscope 1 with a longflexible endoscope shank 2, at the proximal end of which a handle 3 isarranged.

The flexible shank 2 has a distal shank portion 4, a middle shankportion 5, and a proximal shank portion 6. Work channels (not shown) arearranged in the endoscope shank 2 and are used, for example, to receiveoptical fibers of the endoscope optics system, electrical lines and/ormedical instruments.

As will be seen from FIG. 2, the outermost distal shank portion 4 isparticularly flexible and is able to pivot in different directions. Thepivoting of the distal shank portion 4 is effected via a pull mechanism7 (shown in FIGS. 3 and 4) and a control device 8 arranged on the handle3, which control device 8, in the illustrative embodiment shown in FIG.1, is designed as an adjustment lever 9, which is adjustable in thedirection of the arrows 10.

The handle 3 also has, at the proximal end, an eyepiece 11 and, at thedistal end of the handle 3, a work channel entrance 12 through which,for example, a medical instrument can be introduced into a work channelof the endoscope shank 2.

As will be seen from FIG. 2, the distal shank portion 4 of the endoscopeshank 2 can be deflected up and down through almost 180° from thestraight-ahead position shown in FIG. 1. Further deflections of up to210°, and deflections of the distal shank portion 4 in more than justtwo directions, are also possible.

The deflection of the distal shank portion 4 is effected via a pullmechanism 7, which engages on the distal shank portion 4 and which, inthe embodiment shown in FIG. 3, is composed of two Bowden cables 13secured on the distal shank portion 4, which Bowden cables 13 aresecured at the proximal end on the control device 8 of the handle 3. Byactuation of the adjustment lever 9 of the control device 8 in thedirection of the arrows 10, the distal shank portion 4 is pivoted up ordown in the desired direction.

For deflecting the distal shank portion 4 in more than two directions,the control device 8, in an alternative embodiment of the endoscope 1,has two adjustment levers 9: one adjustment lever 9 for pivoting thedistal shank portion 4 up and down, and one adjustment lever 9 forpivoting the distal shank portion 4 to the right and left. With thesetwo adjustment levers 9, all directions are then also possible bycombination of these pivoting directions.

The structure of the shank portions 4, 5 and 6 is described in moredetail below with reference to the illustrations in FIGS. 3 to 5.

To give the endoscope shank 2 the required flexibility and at the sametime sufficient bending strength and shear stability, all the shankportions 5, 6 arranged proximally from the outer distal shank portion 4,when viewed in the longitudinal direction of the shank body, havereversibly deformable spring elements 14.

In the embodiments shown in the illustrations in FIGS. 3 to 5, allspring elements 14 of the shank portions 5, 6 arranged proximally fromthe outer distal shank portion 4, when viewed in the longitudinaldirection of the shank body, are designed as reversibly deformablespring rods 15 extending in the longitudinal direction of the shankbody.

In all of the embodiments shown, the outermost distal shank portion 4 iscomposed of individual segments 16 connected to each other in anarticulated manner.

In the embodiment shown in FIG. 3, the distal shank portion 4, forattachment to the pull mechanism 7, is mounted between two Bowden cableholders 17 at the distal end and proximal end, wherein the proximalBowden cable holder 17 serves as an abutment for the Bowden cablesheath, while the Bowden cable itself is mounted on the distal Bowdencable holder 17. By actuation of the control device 8 on the handle 3,the distal shank portion 4 can in this way be pivoted up and down.

The middle shank portion 5 of this depicted embodiment is composed oftwo spring rods 15, which are integrally bonded to the proximal Bowdencable holder 17 of the distal shank portion 4. As will also be seen fromFIG. 4, the two spring rods 15 of the middle shank portion 5 are woundhelically about each other and, further on in the longitudinal directionof the middle shank portion 5, are connected to each other and mutuallyfixed at some areas, preferably punctual, by weld spots 18. The integralbonding of individual spring rods 15 to each other is preferablyeffected by means of laser welding.

By means of the spring rods 15 being wound helically about each other,the bending strength and torsional stability of the shank portions 5, 6so configured are increased. Winding the spring rods 15 about each otheralso has the advantage that, upon bending of the endoscope shank 2,there is no preferred bending direction, and instead the endoscope shank2 can be bent with approximately the same force in all directions.

The illustration in FIG. 4 shows an enlarged and schematic detailed viewof part of the middle shank portion 5 and of the proximal shank portion6, as can be used for the design of the distal shank portion 4 describedabove with reference to the illustration in FIG. 3.

At the transition to the proximal shank portion 6, a third, additionalspring rod 15 is integrally bonded to the two spring rods 15 of themiddle shank portion 5, preferably by means of laser welding. As willalso be seen from FIG. 4, the additional spring rod 15 of the proximalshank portion 6, extending in the longitudinal direction of the shankbody, is arranged laterally on the spring rods 15 coming from theprevious middle shank portion 5 and is wound helically about the twospring rods 15 of the middle shank portion 5 and, further on in thelongitudinal direction of the proximal shank portion 6, they areconnected to each other and mutually fixed at some areas, preferablypunctual, by weld spots 18.

For designing the spring elements 14 designed as spring rods 15, bothflat and also round metal springs, preferably of spring steel, can beused. Round spring rods 15 have the advantage that they have nopreferential direction upon bending, whereas flat spring rods 15 areable to be easily bent only in two directions.

In the illustrative embodiments shown, the endoscope shank 2 is composedof three shank portions 4, 5 and 6. Alternatively, it is of course alsopossible for the shank to be constructed from just two shank portions orfrom more than three shank portions. The structure of the individualshank portions is advantageously such that the degree of flexibility ofthe individual shank portions decreases from the distal end to theproximal end, starting from the most flexible, distal shank portion 4,that is to say the shank portions become increasingly less flexible orstiffer.

The degree of flexibility of the individual shank portions 5 and 6relative to each other can be adjusted by the choice of material and thegeometry (length, shape, diameter) of the spring rods 15, the number ofthe spring rods 15 and/or the number of the windings of the spring rods15 about each other and/or the number and position of the weld spots 18.

The helical winding of the spring rods 15 about each other can beconfigured in each shank portion 5, 6 with the same number or adifferent number of windings, and with the same pitch or a differentpitch of the windings. More windings per unit of length result in astiffening of the shank portion 5 or 6, whereas fewer windings per unitof length make the respective shank portion 5 or 6 more flexible.

The use of the spring rods 15 as spring elements 14 permits simple andcost-effective production of the flexible endoscope shank 2, such thatthe latter can even be produced and used as a disposable article.

As is shown schematically in FIG. 5, the shank portions 4, 5 and 6 canbe enclosed by an elastic outer sheath 19, preferably a hose. This outersheath 19 then surrounds the spring elements 14 and segments 16, andalso the work channels arranged coaxially with respect to the springelements 14. The outer sheath 19 is advantageously designed such thatthe work channels, extending in the longitudinal direction of theendoscope shank 2, are formed directly in the material of the outersheath 19, as a result of which the assembly of the endoscope shank 2 ismade much easier.

According to an alternative embodiment of the endoscope shank, thespring elements 14 and segments 16, and also the work channels arrangedcoaxially with respect to the spring elements 14, are covered by a kindof net stocking, which is then encased subsequently by the outer sheath19.

A flexible endoscope shank 2 constructed in the manner described aboveis characterized in that, while being of a simple design and being ableto be produced cost-effectively, it has the required flexibility, inparticular in the distal shank portion 4, at the same time withsufficient bending strength, shear stability and torsional stability.

List of reference signs 1 endoscope 2 endoscope shank 3 handle 4 distalshank portion 5 middle shank portion 6 proximal shank portion 7 pullmechanism 8 control device 9 adjustment lever 10 arrow 11 eyepiece 12work channel entrance 13 Bowden cable 14 spring element 15 spring rod 16segment 17 Bowden cable holder 18 weld spot 19 outer sheath

1. A flexible endoscope shank with a shank body which, viewed in thelongitudinal direction of the endoscope shank, is composed of at leasttwo shank portions with different degrees of flexibility, wherein atleast one shank portion is composed of at least one spring element, andwherein all the spring elements of the shank portions, which, viewed inthe longitudinal direction of the shank body, are arranged proximallyfrom the outer distal shank portion, are designed as reversiblydeformable spring rods extending in the longitudinal direction of theshank body, wherein, viewed in the longitudinal direction of the shankbody from the distal end to the proximal end, each of the shank portionshaving at least one spring rod has at least one further spring rod,which is integrally bonded to the other spring rods of the respectiveshank portion.
 2. The flexible endoscope shank as claimed in claim 1,wherein the at least one further spring rod, extending in thelongitudinal direction of the shank body, is arranged laterally on theother spring rods of the respective shank portion.
 3. The flexibleendoscope shank as claimed in claim 1, wherein each shank portion of theshank portions arranged proximally from the outer distal shank portion,when viewed in the longitudinal direction of the shank body, has atleast two spring rods, each of which has a longitudinal extent reachingas far as the proximal end of the shank body.
 4. The flexible endoscopeshank as claimed in claim 1, wherein the spring rods of each shankportion are wound helically about each other and/or are wound helicallyabout the spring rods of the shank portions which, viewed in thelongitudinal direction of the shank body, are located distally.
 5. Theflexible endoscope shank as claimed in claim 4, wherein the spring rodswound helically about each other are integrally bonded to each other atsome areas, preferably punctual.
 6. The flexible endoscope shank asclaimed in claim 4, wherein the spring rods of the individual shankportions are wound, with the same or a different number of windings,about the spring rods of the shank portions which, viewed in thelongitudinal direction of the shank body, are located distally orproximally.
 7. The flexible endoscope shank as claimed in claim 1,wherein the degree of flexibility of the individual shank portionsdecreases from the distal end to the proximal end.
 8. The flexibleendoscope shank as claimed in claim 1, wherein the outermost distalshank portion is composed of individual segments connected to each otherin an articulated manner.
 9. The flexible endoscope shank as claimed inclaim 1, wherein the outermost distal shank portion pivotable via a pullmechanism engaging on the distal shank portion.
 10. The flexibleendoscope shank as claimed in claim 1, wherein all the shank portionscan be enclosed by an elastic outer sheath, preferably a hose.
 11. Theflexible endoscope shank as claimed in claim 10, wherein work channels,extending in the longitudinal direction of the shank body, are arrangedin the outer sheath.
 12. An endoscope, characterized by a flexibleendoscope shank as claimed in claim 1.